Surgical tools having electromagnetic tracking components

ABSTRACT

A surgical tool having an electromagnetic (EM) sensor component is provided. The surgical tool has a flexible shaft portion. Additionally, the surgical tool has a rigid portion attached to the flexible shaft portion. The rigid portion comprises at least one EM sensor within the rigid portion. The at least one EM sensor comprises an extended core portion surrounded by a coil. Additionally, the at least one EM sensor generates a change in voltage when exposed to an electromagnetic field.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/287,370 entitled “Surgical Tools HavingElectromagnetic Tracking Components,” filed Jan. 26, 2016, thedisclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND

1. Field of the Invention

The field of the present application pertains to medical devices. Moreparticularly, the field of the invention pertains to surgical toolshaving electromagnetic tracking components and methods of tracking thesame.

2. Description of the Related Art

Surgical tools may be used to perform a surgical procedure on a patient.The surgical tools may include endoscopes, catheters, ureteroscopes, orother similar devices. Endoscopy is a widely-used, minimally invasivetechnique for both imaging and delivering therapeutics to anatomicallocations within the human body. Typically a flexible endoscope is usedto deliver tools to an operative site inside the body—e.g., throughsmall incisions or a natural orifice in the body—where a surgicalprocedure is to be performed. Endoscopes may have imaging, lighting andsteering capabilities at the distal end of a flexible shaft enablingnavigation of non-linear lumens or pathways.

SUMMARY

In one aspect of the invention, surgical tools comprise one or moreelectromagnetic (EM) sensors that may be used to track placement and/ormovement of the surgical tools during a surgical procedure. In examples,the surgical tools may interact with a field that is generated within anEM system for tracking of surgical tools. In particular, the one or moresensors associated with a surgical tool may be tracked based oninteractions of the one or more sensors with an electromagnetic field.

Examples of surgical tools having EM sensors that may be used astracking components may include endoscopes having one or more EM sensorsdisposed at the tip of the endoscope. In examples where an endoscope hastwo EM sensors, the EM sensors may be placed at oblique angles to oneanother so as provide additional orientation vectors (for example, butnot limited to, roll, pitch, and yaw) that may be determined bycomparing interactions of each EM sensor with an electromagnetic field.In additional examples, a surgical tool having one or more EM sensorsmay include an inwardly extended core so as to enhance sensorsensitivity. In further examples, a surgical tool having one or more EMsensors may include an outwardly extended core for sensing of forceand/or mechanical palpitations.

Additional examples of surgical tools having EM sensors that may be usedas tracking components may include catheters having a plurality of EMsensors placed along the length of the surgical tool. In particular, EMsensors may be placed at predetermined distances along a surgical toolso as to allow the tracking of a portion of the length of the surgicaltool within a patient. By tracking a portion of the length of thesurgical tool within a patient, the orientation of the surgical tool maybe determined. In particular, sensors placed along a length of thesurgical tool may be used to detect the changing shape of the surgicaltool as it moves, such as when a catheter moves within a patient duringsurgery.

In one aspect of the invention, a surgical tool having anelectromagnetic (EM) sensor component is provided. The surgical toolcomprises a flexible shaft portion. Additionally, the surgical toolcomprises a rigid portion attached to the flexible shaft portion. Therigid portion comprises at least one EM sensor within the rigid portion.Additionally, the at least one EM sensor comprises an extended coreportion surrounded by a coil. Further, the at least one EM sensorgenerates a change in voltage when exposed to an electromagnetic field.

In another aspect of the invention, a surgical tool having anelectromagnetic (EM) sensor component is provided. The surgical toolcomprises a flexible shaft portion. Additionally, the surgical toolcomprises a rigid portion attached to the flexible shaft portion. Therigid portion comprises two EM sensors within the rigid portion.Additionally, at least one EM sensor of the two EM sensors comprises anextended core portion surrounded by a coil.

In a further aspect of the invention, an electromagnetic (EM) system fortracking a surgical tool having at least one EM sensor integratedtherein is provided. The EM system comprises a plurality of fieldgenerator coils disposed within a surgical bed, wherein the fieldgenerator coils are configured to generate an electromagnetic fieldwithin a control volume. Additionally, the EM system comprises an EMsystem controller configured to activate the field generator coils togenerate the electromagnetic field within the control volume. The EMsystem also comprises at least one EM sensor integrated within asurgical tool, wherein the at least one EM sensor has an extended core,and wherein the at least one EM sensor is configured to generate asensor signal in response to the electromagnetic field when the at leastone EM sensor is located inside the control volume.

In an additional aspect of the invention, another surgical tool havingan electromagnetic (EM) sensor component is provided. The surgical toolcomprises a flexible shaft portion. Additionally, the surgical toolcomprises a plurality of EM sensors positioned along the flexible shaftportion. The plurality of EM sensors are placed with a predetermineddistance between successive EM sensors. Additionally, each EM sensor ofthe plurality of EM sensors comprises a core portion surrounded by acoil. At least one EM sensor of the plurality of EM sensors has a forcesensing component. Further, each EM sensor of the plurality of EMsensors generates a change in voltage when exposed to an electromagneticfield.

It shall be understood that different aspects of the invention can beappreciated individually, collectively, or in combination with eachother. Other objects and features of the present invention will becomeapparent by a review of the specification, claims, and appended figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described, by way of example, and with referenceto the accompanying drawings, in which:

FIG. 1 illustrates a perspective view of an internal cross-section of anendoscope having electromagnetic (EM) sensors, in accordance with someembodiments;

FIGS. 2A and 2B illustrate configurations of two EM sensors within anendoscopic tip, in accordance with some embodiments;

FIG. 3 illustrates a schematic of an EM tracking surgical system, inaccordance with some embodiments;

FIG. 4 illustrates a schematic circuit diagram of an EM trackingsurgical system, in accordance with some embodiments;

FIG. 5 illustrates a front view of an endoscopic tip having EM sensorswithin, in accordance with some embodiments;

FIG. 6 illustrates a view of an internal cross-section of an endoscopictip having EM sensors within, in accordance with some embodiments;

FIG. 7 illustrates a side view of a cross-section of an endoscope withEM sensors within, in accordance with some embodiments;

FIG. 8 illustrates a side view of a cross-section of an endoscope withEM sensors having an internally extending core, in accordance with someembodiments;

FIG. 9 illustrates a side view of a cross-section of an endoscope withEM sensors having an externally extending core, in accordance with someembodiments;

FIG. 10 illustrates a catheter having external EM sensors, in accordancewith some embodiments; and

FIG. 11 illustrates schematic views of an EM tracking surgical systemhaving reconfigurable bed portions, in accordance with some embodiments.

DETAILED DESCRIPTION

Although certain preferred embodiments and examples are disclosed below,the inventive subject matter extends beyond the specifically disclosedembodiments to other alternative embodiments and/or uses, and tomodifications and equivalents thereof. Thus, the scope of the claimsappended hereto is not limited by any of the particular embodimentsdescribed below. For example, in any method or process disclosed herein,the acts or operations of the method or process may be performed in anysuitable sequence and are not necessarily limited to any particulardisclosed sequence. Various operations may be described as multiplediscrete operations in turn, in a manner that may be helpful inunderstanding certain embodiments; however, the order of descriptionshould not be construed to imply that these operations are orderdependent. Additionally, the structures, systems, and/or devicesdescribed herein may be embodied as integrated components or as separatecomponents.

For purposes of comparing various embodiments, certain aspects andadvantages of these embodiments are described. Not necessarily all suchaspects or advantages are achieved by any particular embodiment. Thus,for example, various embodiments may be carried out in a manner thatachieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other aspects or advantages as mayalso be taught or suggested herein.

1. Integrating EM Sensors with Surgical Tools

Surgical tools having one or more EM sensors may be provided. In someexamples, EM sensors may be embedded within surgical tools. In someexamples, EM sensors may be integrated with surgical tools. In someexamples, EM sensors may be coupled to one or more external portions ofsurgical tools.

Surgical tools as discussed herein may include endoscopes, catheters,ureteroscopes, or other similar devices. Accordingly, FIG. 1 illustratesa perspective view 100 of an internal cross-section of an endoscopehaving electromagnetic (EM) sensors 120, in accordance with someembodiments. As seen in FIG. 1, the internal cross-section of theendoscope comprises a rigid portion 105 and a flexible portion 130. Therigid portion 105 may comprise a tip of the endoscope. In examples, theEM sensors 120 within the endoscope may be used to spatially track thetip of the endoscope. Additionally, the flexible portion 130 may formpart of a shaft of the endoscope. The flexible portion 130 may beoperable connected to a robotic arm. In examples, endoscope that ispartially illustrated in FIG. 1 may be used in conjunction with arobotic arm to assist in surgery of a patient.

The rigid portion 105 of an endoscope may include a camera 110,illumination sources 115, and a channel 125 for holding various surgicaltools. Examples of illumination sources 115 may include fiberoptics-illumination sources. Additionally, as seen in FIG. 1, the rigidportion may include a pair of EM sensors 120 that may be used astracking components. In particular, the EM sensors 120 may be used fortracking a position of the rigid portion 105. Each EM sensor 120 may besurrounded by coils that may interact with an EM field that is generatedby field generator coils. In examples, the system provided may be usedfor alternating current (AC) EM tracking. In other examples, the systemmay be used for direct current (DC) EM tracking. In examples, an EMsensor associated with a surgical tool may be tracked when voltage isinduced within a sensor coil that is placed within the electromagneticfield. In examples, the system provided may be used for alternatingcurrent (AC) EM tracking. In other examples, the system may be used fordirect current (DC) EM tracking. As the EM sensors 120 interact with theEM field, the EM sensors 120 may output voltage information which isrelated to a change in the EM field as the position and/or orientationof the EM sensors 120 changes. The change in the position and/ororientation of the EM sensors 120, in turn, may be associated with thechange in the location of the rigid portion 105 of the surgical toolthat contains the EM sensors 120. Small variations in position can bedetected based on the interaction of EM sensors 120 with the EM field.The positional variations can have a spatial resolution of less thanabout 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, or 1 mm. Insome cases, the spatial resolution may be greater than about 10 mm.

In additional examples, the position of the endoscope may be determinedbased on input from the EM sensors 120 as well as input from camera 110.In particular, an initial position of the rigid portion 105 of thesurgical tool may be determined based on interactions of the EM sensors120 with an EM field, and the position of the rigid portion 105 may beconfirmed based on input received from camera 110. Alternatively, aninitial position of the rigid portion 105 of the surgical tool may bedetermined based on input received from camera 110, and the position ofthe rigid portion 105 may be confirmed based on an assessed location ofthe EM sensors 120.

In some examples, two EM sensors may be positioned within a surgicaltool. In examples where the two EM sensors are positioned obliquely withrespect to one another, a positional state of the surgical tool may bedetermined in six degrees of freedom. In some examples, EM sensors, suchas EM sensors 120 of FIG. 1, may be positioned within surgical tools indifferent configurations. EM sensors may be formed of coils wrappedaround a ferrous core. In examples, the ferrous core may compriseferrites. In additional examples, the ferrous core may comprise softferrites. In further examples, the ferrous core may comprise hardferrites. In some examples, the ferrous core may comprise a highpermeability metal alloy. The diameter of each EM sensor may be 300 μm.In examples, the diameter of an EM sensor may be 250 μm, may be 200 μm,may be 150 μm, may be 100 μm, may be 50 μm, or may be less than 50 μm.In further examples, the diameter of an EM sensor may be 350 μm, may be400 μm, may be 450 μm, may be 500 μm, may be 800 μm, 1 mm, 1.5 mm, ormay be more than 1.5 mm. Additionally, in examples, the outer diameterof the EM sensor may be minimized. Two examples of configurations of EMsensors are provided in FIGS. 2A and 2B. In particular, FIGS. 2A and 2Billustrate configurations of two EM sensors within an endoscopic tip, inaccordance with some embodiments.

FIG. 2A illustrates an endoscopic tip 200 having EM sensors 210, 220positioned obliquely with respect to one another. In some examples, thetwo sensors 210, 220 may be placed at a same distance from an end of theendoscope. In some examples, one of sensors 210, 220 may be placedcloser to a tip of an endoscope and one of sensors 210, 220 may beplaced further from a tip of an endoscope. Positioning EM sensors 210,220 oblique to each other provides a benefit of assessing orientation ofa surgical tool in addition to assessing a location of the surgicaltool. In particular, interactions of the EM sensors 210, 220 with agenerated EM field may be assessed to determine yaw, pitch, and roll ofa portion of a surgical tool that contains EM sensors 210, 220. Thisdetermination is made based on the voltage that is produced by each EMsensor 210, 220 as each sensor passes through the EM field. In examples,the voltage is generated by the intersection of an electric field of thesensor with the magnetic flux lines in the EM field. The change involtage may then be used to determine the spatial position of eachsensor as the sensors move within a controlled volume, such as acontrolled volume that contains the EM field. Additionally, when the EMsensors are positioned obliquely to one another, as seen in EM sensors210, 220 of FIG. 2A, the difference in angled position may be assessedto determine an orientation of the surgical tool containing the EMsensors, such as endoscopic tip 200 that contains EM sensors 210, 220.In additional examples, the EM sensors may be positioned acutely to oneanother (not shown). When the EM sensors are positioned acutely to oneanother, the difference in angled positioned may also be assessed todetermine an orientation of the surgical tool containing the EM sensors.

In contrast, FIG. 2B illustrates an endoscopic tip 250 having EM sensors260, 270 positioned generally parallel to one another. Given that EMsensors 260, 270 have generally the same orientation, the sensors may beused to determine a location of the endoscopic tip 250 within a patient.In particular, the interaction of sensors 260, 270 with an EM field maybe used to generate a voltage which may identify a location of theendoscopic tip 250 that includes sensors 260, 270 withinthree-dimensional special coordinates. However, since the sensors 260,270 are not positioned at an oblique or acute angle with respect to eachother, it may be more difficult to assess a particular orientation ofthe endoscopic tip 250. In particular, when sensors 260, 270 share asame general orientation, it may be more difficult to distinguish eachof the sensors 260, 270 from the other. In examples where thesensitivity of the detection of the sensors 260, 270 is high enough,though, that the sensors 260, 270 may be distinguished from each othereven as the sensors 260, 270 are generally parallel, the tracking of theindividual sensors 260, 270 with respect to each other may be used toassess these additional three degrees of freedom. Even in this example,however, providing EM sensors at different orientations would provide abenefit of more easily distinguishing each of the EM sensors from oneanother, as discussed in FIG. 2A.

Although FIGS. 2A and 2B illustrate endoscopic tips 200, 250 having EMsensors 210, 220 and 260, 270, respectively, additional examples may beprovided where an endoscopic tip has one EM sensor integrated therein.For example, an endoscopic tip may have one EM sensor integrated thereinat a position similar to EM sensor 210 within endoscopic tip 200;similar to EM sensor 220 within endoscopic tip 200; similar to EM sensor260 within endoscopic tip 250; or similar to EM sensor 270 withinendoscopic tip 250. In additional examples, an EM sensor may be locatednear a central axis of an endoscopic tip. In particular, an EM sensormay partially overlap a central axis of the endoscopic tip. In furtherexamples, an EM sensor may be located near the periphery of theendoscopic tip.

The one or more EM sensors may be tracked using an EM tracking surgicalsystem, as discussed below in FIG. 3. In particular, an EM trackingsurgical system may be provided in which field generator coils areprovided so as to generate an EM field over at least a portion of asurgical bed. In examples, field generator coils may be incorporatedwithin a surgical bed, and/or the field generator coils may be otherwisepositioned relative to the surgical bed and/or to a patient on thesurgical bed. As the one or more EM sensors of a surgical tool interactwith the EM field, the location of the surgical tool may be determined.Additionally, movements of the surgical tool may be tracked based on theinteractions with the EM field.

In additional examples, when two EM sensors are positioned within asurgical tool such that one of the two EM sensors has an extended core,the measured difference between the two EM sensors may be assessed toprovide additional sensitivity with respect to the location of thesurgical tool. Further, in examples when an extended core of an EMsensor is extended externally from the surgical tool, a force perceptioncomponent may be utilized to determine a position of the surgical toolwith respect to nearby tissue that is detected using the externallyextended core of the EM sensor.

In additional examples, EM sensors may be placed along a surgical toolso as to determine a shape and location of the surgical tool within apatient. For example, a plurality of EM sensors may be placed along asurgical tool, such as a catheter. By setting EM sensors atpredetermined distances along a surgical tool, the interactions of theEM sensors with a generated field may be assessed individually andcollectively so as to determine characteristics about the position ofthe surgical tool with respect to the patient.

2. Tracking Surgical System Components

FIG. 3 illustrates a schematic of an EM tracking surgical system, inaccordance with some embodiments. As shown in FIG. 3, EM trackingsurgical system 300 may comprise a surgical bed 302 on a base 301, aplurality of field generator coils 303, an EM system controller 308, aswitch module 310, a working volume 312, and a position sensor 316.

The surgical bed 302 may be configured to support a patient. A physicianmay perform a surgical procedure on the patient while the patient isplaced on the surgical bed 302. In some embodiments, the surgical bed302 may comprise multiple sections that are movable relative to oneanother. In those embodiments, the patient's body can be moved intodifferent positions by moving different sections of the surgical bed 302relative to one another. Alternatively, the surgical bed 302 may beformed monolithically as a single rigid structure.

Field generator coils 303 may be embedded or integrated along edgeportions of the surgical bed 302. For example, as shown in FIG. 3, theplurality of field generator coils 303 may be embedded along a length ofthe surgical bed 302 in two rows. The rows may extend parallel to eachother along the edge of the surgical bed 302. The placement of the fieldgenerator coils 303 along the edges of the surgical bed 302 can allowunobstructed use of fluoroscopy to image the patient's body during asurgical procedure. In additional embodiments, the field generator coilsmay be placed in other positions within, or around, the surgical bed 302so as to generate a working volume 312 that may be used to track sensor316. In some examples, the field generator coils may be incorporatedwithin the surgical bed 302. In further examples, the field generatorcoils may be otherwise positioned relative to a patient and/or asurgical bed 302.

In examples, the shape of the working volume 312 may be determined basedon the shape and strength of the EM field generated by the fieldgenerator coils 303 as activated by the EM system controller 308. Inparticular, the strength of the EM field that is generated may becontrolled by EM system controller 308. In some examples, the workingvolume 312 may be defined by the volume that includes the presence of anEM field that is strong enough to generate a detectable voltage when itinteracts with an EM sensor 316, such as EM sensors that may be disposedwithin surgical tools. In examples, an EM field may have the strength of1 nanotesla (nT), 10 nT, 100 nT, 500 nT, 1 microtelsa (μT), 10 μT, 100μT, 500 μT, 1 millitesla (mT), 10 mT, 100 mT, or more than 100 mT.

The field generator coils 303 may be fixed in place relative to oneanother. For example, the field generator coils may be spaced apart by apredetermined distance and/or at a predefined pitch along the edges ofthe surgical bed 302. In examples, the field generator coils may benominally fixed relative to the surgical bed 302 in a global coordinatesystem. Any portion of the surgical bed 302 may serve as an origin ofthe global coordinate system. In some embodiments, a datum point thatlies substantially above a center portion of the surgical bed 302 mayserve as the origin of the global coordinate system. In thoseembodiments, the positions of the field generator coils may be definedrelative to the datum point.

In some embodiments, when the surgical bed 302 comprises multiplesections that are movable relative to one another, the field generatorcoils 303 may not be fixed in position relative to one another. Instead,the field generator coils 303 may be located on one or more movablesections, and can move relative to one another when one or more sectionsof the surgical bed 302 move. In those embodiments, global tracking of asurgical tool can be facilitated by adding sensors to the surgical bed302 that can detect changes in the configuration of the surgical bed302.

As shown in FIG. 3, working volume 312 may be generated based on theplacement of field generator coils 303. In particular, an EM systemcontroller 308 may be configured to provide electrical current pulses tothe field generator coils 303 to generate an EM field comprising theworking volume 312. The EM system controller 308 can selectivelyactivate or unactivate the EM field by controlling one or more switchesin the switch module 310. In particular, electrical current pulses maybe provided from the EM system controller 308 to the field generatorcoils 303 via one or more switches in the switch module 310.

The switches may include electronic switches such as power MOSFETs,solid state relays, power transistors, and/or insulated gate bipolartransistors (IGBTs). Different types of electronic switches may beprovided for controlling current to the field generator coils 303. Anelectronic switch may utilize solid state electronics to control currentflow. In some instances, an electronic switch may have no moving partsand/or may not utilize an electro-mechanical device (for example, butnot limited to, traditional relays or switches with moving parts). Insome instances, electrons or other charge carriers of the electronicswitch may be confined to a solid state device. The electronic switchmay optionally have a binary state (for example, but not limited to,switched-on or switched-off). The electronic switches may be used tocontrol current flow to the field generator coils. The operation ofswitches to selectively activate the field generator coils 303 isdescribed with reference to FIG. 4, below.

In some embodiments, the EM system controller 308 may be located on thesurgical bed 302, for example on a base 301 configured to support thesurgical bed 302. In some embodiments, the EM system controller 308 maybe located remotely from the surgical bed 302. For example, the EMsystem controller 308 may be disposed in a remote server that is incommunication with the field generator coils 303 and the switch module310. The EM system controller 308 may be software and/or hardwarecomponents included with the server. The server can have one or moreprocessors and at least one memory for storing program instructions. Theprocessor(s) can be a single or multiple microprocessors, fieldprogrammable gate arrays (FPGAs), or digital signal processors (DSPs)capable of executing particular sets of instructions. Computer-readableinstructions can be stored on a tangible non-transitorycomputer-readable medium, such as a flexible disk, a hard disk, a CD-ROM(compact disk-read only memory), and MO (magneto-optical), a DVD-ROM(digital versatile disk-read only memory), a DVD RAM (digital versatiledisk-random access memory), or a semiconductor memory. Alternatively,the program instructions can be implemented in hardware components orcombinations of hardware and software such as, for example, ASICs,special purpose computers, or general purpose computers.

The EM system controller 308 may also be provided at any other type ofexternal device (for example, but not limited to, a remote controllerfor controlling the surgical bed 302 and/or a surgical tool, any movableobject or non-movable object, etc.). In some instances, the EM systemcontroller 308 may be distributed on a cloud computing infrastructure.The EM system controller 108 may reside in different locations where theEM system controller 303 is capable of controlling the switch module 310and selectively activating the field generator coils 303 based on thespatial information of the position sensor 316. For instance, EM systemcontroller 108 may activate an FG coil when a position sensor comeswithin a threshold distance of the FG coil. Additionally, EM systemcontroller 308 may de-activate an FG coil when a position sensor movesbeyond a threshold distance from the FG coil.

The position sensor 316 may be disposed in or on a portion of a surgicaltool. For example, in some embodiments, the position sensor 316 may bedisposed at a distal end of the surgical tool. Examples of surgicaltools may include endoscopes, catheters, ureteroscopes, forceps,different kinds of scopes, or other similar devices or surgicalaccessories.

A position sensor, such as position sensor 316, may be configured togenerate an electrical signal (for example, but not limited to, voltageor current signal) in response to EM fields generated by the fieldgenerator coils 303. Position sensor 316 may be an EM sensor. Asposition sensor 316 moves within a control volume 312, the interactionof the position sensor 316 with the EM field within the control volume312 may cause electrical signals to be generated. The electrical signalsmay vary as the position sensor 316 moves between different locationswithin a control volume 312. Additionally, electrical signals may varyas the position sensor 316 moves between different control volumes. TheEM system controller 308 may be configured to receive electrical signalsfrom the position sensor 316. Additionally, the EM system controller 308may analyze the signals to compute a local position of the sensor 316.The local position of the sensor 316 may be computed relative to a localcoordinate system. The local coordinate system may be defined at activefield generator coils 303 corresponding to the control volume 312 inwhich the position sensor 316 is located.

The EM system controller 308 may be further configured to compute aglobal position of the sensor 316 relative to a global coordinatesystem. The global coordinate system may be defined at the surgical bed302 (for example, but not limited to, above a center portion of thesurgical bed 302). The global position of the sensor 316 may be computedbased on: (1) the local position of the sensor 316 within the controlvolume 312 above active field generator coils 303, and (2) the positionof the active field generator coils 303 relative to the surgical bed302. The global position of the sensor 316 may be used to determine aposition of a surgical tool relative to a patient on the surgical bed302. Additionally, the EM system controller 308 may be configured tocontrol the switch module 310 based on one or more inputs. The controlof the switch module 310, and the selective activation of one or moresubsets of field generator coils 303, may be manual and/or automatic.

In some embodiments, the EM system controller 308 may control the switchmodule 310 based on a user input corresponding to a selection of aregion (or working volume 312) of the surgical bed 302 where tracking ofa surgical tool is desired. For example, a physician may plan to performa surgical procedure on a patient in a region within the working volume312. Accordingly, the physician or the physician's assistant may providean input to the EM system controller 308 to activate the field generatorcoils 303, so that movement of the surgical tool can be tracked withinthe first control volume via the position sensor 316.

In some embodiments, a local position of the sensor 316 may bedetermined based on distances between the sensor 316 and a plurality ofreference points in different local coordinate systems. The differentlocal coordinate systems may within and/or outside control volume 312.The EM system controller 308 may be configured to determine a minimumdistance from those distances, and activate field generator coils 303corresponding to the control volume 112 based on the minimum distance.Additionally, during a surgical procedure, the EM system controller 308may be configured to track the position and/or movement of the sensor316 within a control volume 312 corresponding to active field generatorcoils 303.

3. Switching Circuit

FIG. 4 illustrates a schematic circuit diagram of an EM trackingsurgical system, in accordance with some embodiments. As shown in FIG.4, an EM tracking surgical system 400 may comprise field generator coils403 electrically connected to a power supply 418. An EM systemcontroller 408 may be in operable communication with a switch K1 and aposition sensor 416. Switch K1 may be located in a switch module (forexample, but not limited to, switch module 310 of FIG. 3). The EM systemcontroller 408 may be configured to selectively activate field generatorcoils 403 based on a position and/or movement of the position sensor 416within and/or outside a control volume (for example, but not limited to,control volumes 312 of FIG. 3).

In examples, an EM system controller 408 may activate field generatorcoils when a position sensor 416 within a surgical tool indicates thatthe surgical tool is nearing a working volume that is associated with apatient. For example, an EM system controller 408 may activate fieldgenerator coils when a position sensor 416 within a surgical toolindicates that the surgical tool is within a threshold distance of aworking volume that is associated with the patient. In examples, thethreshold distance may be less than 1 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm,6 mm, 8 mm, 10 mm, or more than 10 mm. In additional examples, an EMsystem controller 408 may de-activate field generator coils 403 when aposition sensor 416 within a surgical tool indicates that the surgicaltool has left a working area that is associated with a patient. Forexample, an EM system controller 408 may de-activate field generatorcoils when a position sensor 416 within a surgical tool indicates thatthe surgical tool is beyond a threshold distance of a working volumethat is associated with the patient. In examples, the threshold distancemay be less than 1 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 8 mm, 10 mm,or more than 10 mm. The EM system controller 408 may also activate fieldgenerator coils 403 in response to receiving a request to initiate thefield generator coils 403. In additional examples, the EM systemcontroller 408 may de-activate the field generator coils 403 when apredetermined amount of time has passed without sensing movement of theposition sensor 416.

4. Examples of Surgical Tool Components

In examples, EM sensors may be completely internalized within a surgicalcomponent. As such, an external view of a surgical component may notdirectly indicate the presence of EM sensors. In accordance with thisexample, FIG. 5 illustrates a front view 500 of an endoscopic tip havingEM sensors (not shown) fully integrated within. Having EM sensors fullyintegrated within provides a benefit of encapsulating the sensormaterials so as to prevent exposure of the sensor materials to thepatient, as well as to prevent exposure of potential corrosive materialsto the sensor materials. As seen in FIG. 5, an external view ofendoscopic tip may provide a camera 510, illumination components 515,and a working channel 525.

While the placement of EM sensors may be completely internalized withina surgical tool, the placement of other components of the endoscopic tipas seen in FIG. 5 may be affected by internalized EM sensors within theendoscopic tip. In particular, other components within a surgical tool,such as an endoscopic tip, may be arranged based on placement of the oneor more sensors. For example, illumination sources 515 may be placedcloser to a proximate edge of a face of an endoscopic tip so as to allowan area for one or more EM sensors to reside internally within theendoscopic tip. Additionally, while two illumination sources areillustrated in FIG. 5, other examples may provide a single illuminationsource. In additional examples, more than two illumination sources maybe provided. For example, three, four, five, six, seven, eight, or morethan eight illumination sources may be provided. In these examples, theplacement of the illumination sources may be configured so as to allowfor the placement of at least one EM sensor within a portion of asurgical tool, such as within an endoscopic tip of the surgical tool.

An example of a cross-section of an endoscopic tip having internalizedEM sensors is provided in FIG. 6. In particular, FIG. 6 illustrates aview 600 of an internal cross-section of an endoscopic tip having EMsensors 620 within, in accordance with some embodiments. As seen in FIG.6, EM sensors 620 are positioned relative to a camera 610, illuminationsources 615, and a working channel 625. In particular, EM sensors 620are positioned between illumination sources 615 and the working channel625. While two EM sensors 620 are illustrated in FIG. 6, in otherexamples a single EM sensor may be provided. In additional examples,more than two EM sensors may be provided. For example, three, four,five, six, seven, eight, or more than eight EM sensors may be provided.Additionally, each EM sensor does not need to be within a same area ofthe surgical tool. Although the two EM sensors as shown in FIG. 6 areboth within a tip of an endoscope, additional examples may provide thatEM sensors are provided in staggered placement along a length of asurgical tool and/or along a length of a tip of an endoscope.Additionally, staggered positioning of EM sensors may provide for aneffective lengthening of a sensor area that induces voltage change whenexposed to an EM field. This, in turn, may make a a location and/ororientation of a surgical tool more readily identifiable.

FIG. 7 illustrates a side view 700 of a cross-section of a portion of anendoscope with EM sensors within, in accordance with some embodiments.In particular, FIG. 7 illustrates a rigid portion 705, a camera 710, afirst EM sensor 720 having a core 722, a working channel 725, and aflexible portion 730. Rigid portion 705 may be attached to flexibleportion 730. As seen in FIG. 7, a core 722 of a first EM sensor 720 maystay within the rigid portion 705 of the endoscope. In some examples,the length of the core 722 of the first EM sensor may match the lengthof the coil that surrounds the core 722 of the EM sensor. In additionalexamples, coil that surrounds the core 722 of the EM sensor may have ashort length. In some examples, coil of EM sensor 720 may surround thecore 722 of the EM sensor continuously. In further examples, coil of theEM sensor 720 may surround the core of the EM sensor discontinuously.

While FIG. 7 illustrates a first EM sensor 720, the rigid portion 705may also comprise a second EM sensor (not shown). In examples, a lengthof a second EM sensor may match the length of the first EM sensor 720.In other examples, a length of a second EM sensor may be greater thanthe length of the first EM sensor. In further examples, a length of asecond EM sensor may be shorter than the length of the first EM sensor.

In some examples having a first and a second EM sensor within a surgicaltool, a core of a first EM sensor may be extended so as to increasesensitivity of voltage measurement. In particular, when a core of afirst EM sensor is extended while the core of the second EM sensorremains constant, a voltage that is measured between the first andsecond EM sensors may be assessed to determine a magnitude and adirection of a generated magnetic field. This information may, in turn,be used to determine information associated with a change of position ofthe surgical tool having the first and second EM sensors integratedtherein. Additionally, the determined magnitude and direction of agenerated magnetic field may be used to determine a change inorientation of the surgical tool having the first and second EM sensorsintegrated therein.

In examples, the first EM sensor 820 of the first and second EM sensorsmay have a core that is extended internally. In particular, FIG. 8illustrates a side view 800 of a cross-section of an endoscope portionwith an EM sensor 820 having an internally extending core 822, inaccordance with some embodiments. FIG. 8 provides a first EM sensor 820disposed between a camera 810 and a working channel 825 within anendoscope. As seen in FIG. 8, the internally extending core 822 extendsfrom a rigid portion 805 of the endoscope to a flexible portion 830. Asdiscussed above, extending a core of a first EM sensor 820 may increasethe sensitivity when assessing a change in voltage induced by the firstEM sensor 820 and the second EM sensor (not shown) interacting with anEM field generated by field generator coils that are activated by an EMcontrolling system.

In examples, the use of an extended core, such as extended core 822 offirst EM sensor 820, can boost the sensitivity of voltage measurementinduced by the interaction of the first EM sensor 820 and second EMsensor (not shown) with a generated EM field. In some examples, an EMsensor with an extended core may have increased sensitivity relative toan EM sensor without an extended core based on an aspect ratio of the EMsensor. In particular, by lengthening an EM sensor, sensitivity of theEM sensor may be improved. Similarly, minimizing a length of a sensorstrip while maintaining a length of the core of an EM sensor may alsoincrease an aspect ratio of the EM sensor, thereby also increasingsensitivity of the sensor. In additional examples, sensitivity of an EMsensor may be increased based on a material composition of the EMsensor. In further examples, sensitivity of an EM sensor may be affectedby shape permeability. Shape permeability may be influenced by sensororientation, size, and dimensions in addition to aspect ratio and corematerial as previously discussed.

In other examples, the first EM sensor 920 of the first and second EMsensors may have a core that is extended externally. In particular, FIG.9 illustrates a side view 900 of a cross-section of an endoscope portionwith an EM sensor 920 having an externally extending core 922, inaccordance with some embodiments. In some examples, a diameter of core922 may be less than 1 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, or more than 5mm. FIG. 9 provides a first EM sensor 920 disposed between a camera 910and a working channel 925 within an endoscope. As seen in FIG. 9, theexternally extending core 922 extends from a rigid portion 905 of theendoscope to an external portion of the endoscope. As such, externallyextending core 922 may contact tissue and other materials that may befound at a surgical location within a patient. In examples, theexternally extending core 922 may be used to measure properties ofmaterials, such as tissue, at a surgical site through the application ofmechanical force and/or palpitations. In particular, the externallyextending core 922 may be used to apply force or palpitations and/or maybe used to measure the response of materials to the application of forceor palpitations. As discussed above, extending a core of a first EMsensor 920 may increase the sensitivity when assessing a change involtage induced by the first EM sensor 920 and the second EM sensor (notshown) interacting with an EM field generated by field generator coilsthat are activated by an EM controlling system.

In addition to benefits that may be provided from extending a core 922of first EM sensor 920 based on the increased sensitivity of the EMsensor, an externally extended core 922 may also be used to obtaininformation based on applying a force to materials at a surgical site.In some examples, a force perception structure may be attached to a freeend of an extended core. In some examples, the force perceptionstructure may be ball-shaped so as to maximize surface area for contactas well as to minimize negative invasive effects when the forceperception structure encounters materials, such as tissue, at a surgicalsite. In some examples, the force perception structure may be shaped asa pyramid, cylinder, cube, or a flat sheet, in addition to otherexamples. When the force perception structure comes into contact withmaterial, the force perception structure may generate an output inresponse to the contact interaction. In additional examples, forceapplied to an extended core may be assessed based upon a degree ofdeflection when the extended core is pressed against tissue. In thisexample, the non-extended core of a second EM sensor may be used asreference point for differential measurement between the first EM sensorhaving an externally extended core and the second EM sensor that doesnot have an externally extended core. In additional examples, both thefirst and second EM sensors may have cores that are extended relative toa length of a coiled material provided around the core of the EM sensor.In these examples, however, the length and/or direction of coreextension between the first and second EM sensor may differ so as toprovide a greater differential between voltage measurements between thetwo sensors.

While some examples of surgical tools may have EM sensors integratedwithin the surgical tool, other examples of surgical tools may have EMsensors integrated externally. In some examples, externally integratedEM sensors may be attached to the surgical tool. In particular, FIG. 10illustrates a view 1000 of a catheter 1005 having external EM sensors1010, in accordance with some embodiments. As seen in FIG. 10, theplurality of EM sensors 1010 are located at different locations alongthe length of the catheter 1005. Each of the EM sensors 1010 maygenerate a change in voltage when exposed to an electromagnetic field.By detecting this change in voltage, the location of the catheter may bedetermined. Additionally, as there may potentially be a number oflocation inputs, the change of voltage that is generated by theplurality of EM sensors 1010 may be used to determine a shape of thecatheter 1005. Further, as the catheter moves within a patient, thechange of shape of the catheter may also be determined based on thedetected change of voltage that is measured.

In an example, a minimal interval distance may be provided between eachEM sensor 1010 and a subsequent EM sensor. By providing a minimalinterval distance, interference between EM sensors may be minimized. Insome examples, the interval distance between two adjacent EM sensors maybe in the range of 5-10 cm. In some examples, the interval distance maybe less than 2 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10cm, 11 cm, 12 cm, 13 cm, 14 cm, 15 cm, 20 cm, or more than 20 cm.Additionally, the distance between each EM sensor may differ, such aswithin a particular distance. For example, EM sensors along a cathetermay be between 5 cm and 10 cm apart. In some examples, the EM sensorsalong a catheter may be 5 cm apart. In some examples, the EM sensorsalong a catheter may be 10 cm apart. In some examples, the EM sensorsalong a catheter may be at least 5 cm apart. The spacing between EMsensors may be continuous, may be based on a pattern, and/or may beconsistent within a threshold range of distances.

In additional examples, each EM sensor placed along a surgical tool mayhave a length that extends along the length of the shaft of the surgicaltool that is between 2-4 mm. In some examples, the EM sensor may have alength along the shaft of the surgical tool of less than 1 mm, 1 mm, 2mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 20 mm, 30 mm, 40mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 1 cm, or more than 1 cm.Additionally, in examples, each EM sensor may comprise a core with coilswound around. The core may be a ferrous core. In examples, the core maybe a type of ferrite.

7. EM Tracking Surgical Systems Having Reconfigurable Bed Portions

FIG. 11 illustrates schematic views of an EM tracking surgical systemhaving reconfigurable bed portions, in accordance with some embodiments.Part A of FIG. 11 illustrates a side view of a portion of an EM trackingsurgical system 1100 when a surgical bed is in a first position. Part Bof FIG. 11 illustrates the side view of the system 1100 when thesurgical bed is in a second position.

As shown in FIG. 11, a surgical bed 1102 may comprise reconfigurable bedportions that can move relative to each other. For example, the surgicalbed 1102 may comprise a first bed portion 1102-1 and a second bedportion 1102-2 connected at a hinge 1124 that allows the bed portions tomove (for example, but not limited to, rotate and/or slide) relative toeach other. A first subset of field generator coils 1103-1 may beembedded along a length of the first bed portion 1102-1. A second subsetof field generator coils 1103-2 may be embedded along a length of thesecond bed portion 1102-2. Accordingly, the first and second subsets offield generator coils 1103 may be embedded along a length portion of thesurgical bed 1102.

A first working volume 1112-1 may be defined above the first subset offield generator coils 1103-1, and a second working volume 1112-2 may bedefined above the second subset of field generator coils 1103-2. In someembodiments, the dimensions and/or size of the first and second workingvolumes 1112-1 and 1112-2 may be the same. Alternatively, the dimensionsand/or size of the first and second working volumes 1112-1 and 1112-2may be different.

As shown in FIG. 11, the first and second working volumes may overlap soas to form a first overlapping working volume 1114-1 disposed at aboundary between the first and second subsets of field generator coils1103-1 and 1103-2. The first and second working volumes 1112-1 and1112-2 may be configured to overlap by various amounts. For example, thefirst and second working volumes 1112-1 and 1112-2 may be configured tooverlap by 1%, 2%, 5%, 10%, 15%, 20%, 25%, 30%, or more than 30%. Thefirst and second working volumes 1112-1 and 1112-2 may be configured tooverlap such that one or more position sensors, such as position sensors1116 discussed above, can be accurately tracked and controlled near theboundaries of the control volumes 1112, and as the position sensor(s)1116 moves between adjacent working volumes 1112.

As shown in FIG. 11, a global coordinate system 1120 may be definedabove a center portion of the surgical bed 1102. For example, the globalcoordinate system 1120 may be defined above a boundary line between thefirst bed portion 1102-1 and the second bed portion 1102-2. An origin ofthe global coordinate system 1120 may lie above the center portion ofthe surgical bed 1102 along the Z-direction. The origin of the globalcoordinate system 1120 may also lie at a predetermined location abovethe hinge 1124 when the surgical bed is in the position shown in part Aof FIG. 11. The origin of the global coordinate system 1120 may serve asa datum point from which the positions of a patient's body, the fieldgenerator coils 1103, and the working volume 1112 may be defined.

A first local coordinate system 1122-1 may be defined above a centerportion of the first bed portion 1102-1. Likewise, a second localcoordinate system 1122-2 may be defined above a center portion of thesecond bed portion 1102-2. The first local coordinate system 1122-1 mayor may not have an origin that lies at a center portion of the firstworking volume 1112-1. Similarly, the second local coordinate system1122-2 may or may not have an origin that lies at a center portion ofthe second working volume 1112-2. For example, as shown in part A ofFIG. 11, the origin of the first local coordinate system 1122-1 may liebelow the center portion of the first working volume 1112-1, and inclose proximity to the first bed portion 1102-1. Likewise, the origin ofthe second local coordinate system 1122-2 may lie below the centerportion of the second working volume 1112-2, and in close proximity tothe second bed portion 1102-2.

Vectors may be defined between the global coordinate system 1120 and thelocal coordinate systems 1122-1 and 1122-2. For example, a vector T1 maybe defined from the origin of the first local coordinate system 1122-1to the origin of the global coordinate system 1120. A vector T2 may bedefined from the origin of the second local coordinate system 1122-2 tothe origin of the global coordinate system 1120. In some embodiments,another vector (not shown) may be defined from the origin of the firstlocal coordinate system 1122-1 to the origin of the second localcoordinate system 1122-2. The vectors T1 and T2 may be used to definethe spatial relationship between the first working volume 1112-1 and thesecond working volume 1112-2. In particular, the vectors T1 and T2 maybe used to define the spatial relationship between the first and secondworking volumes 1112-1 and 1112-2 relative to the datum point (forexample, but not limited to, origin of the global coordinate system1120) as the first and second bed portions 1102-1 and 1102-2 moverelative to each other.

As shown in part A of FIG. 11, the first bed portion 1102-1 and thesecond bed portion 1102-2 may initially lie on a same horizontal planeextending along the Y-axis direction. The first and second bed portions1102-1 and 1102-2 may be configured to move relative to each other. Forexample, as shown in part B of FIG. 11, the first bed portion 1102-1 mayrotate by an angle θ in a clockwise direction about an X-axis extendingthrough the hinge 1124. The first bed portion 1102-1 may be rotated, forexample, to lower or raise a portion of a patient's body that issupported by the first bed portion 1102-1. Since the first controlvolume 1112-1 is defined by the EM field generated by the first subsetof field generator coils 1103, the first control volume 1112-1 may alsorotate by the angle θ in a clockwise direction about the X-axis. Asshown in part B of FIG. 11, it may be observed that the origin of thefirst local coordinates system 1122-1 has shifted to a new location.Accordingly, a new vector T1′ may be defined from the shifted origin ofthe first local coordinates system 1122-1 to the origin of the globalcoordinates system 1120, whereby the vector T1′ is different from thevector T1. Since the second bed portion 1102-2 is not rotated relativeto the global coordinates system 1120, the origin of the second localcoordinates system 1122-2 remains unchanged, and therefore the vector T2remains the same. The vectors T1′ and T2 may be used to define thespatial relationship between the first and second working volumes 1112-1and 1112-2 relative to the datum point (for example, but not limited to,origin of the global coordinate system 1120) after the first bed portion1102-1 has moved relative to the second bed portion 1102-2.

Although part B of FIG. 11 illustrates movement of the first bed portion1102-1 relative to the second bed portion 1102-2, the movement betweenthe bed portions is not limited thereto. For example, in someembodiments, the second bed portion 1102-2 may move relative to thefirst bed portion 1102-1. Optionally, the first and second bed portions1102-1 and 1102-2 may simultaneously move relative to each other suchthat the origins of the first and second local coordinate systems shiftto different locations. The relative movement between the bed portions1102-1 and 1102-2 may comprise a rotational motion, a translationalmotion, and/or a combination of rotational and translational motion,about one or more axes. Accordingly, relative movement of the bedportions 1102-1 and 1102-2 in one or more degrees of freedom (forexample, but not limited to, six degrees of freedom) may becontemplated.

In some embodiments, a position, shape, and/or size of the overlappingworking volume 1114 between adjacent working volumes may change when thebed portions move relative to each other. For example, as shown in partA of FIG. 11, a center (or centroid) of the first overlapping workingvolume 1114-1 may be located at the origin of the global coordinatessystem 1120. The first overlapping working volume 1114-1 may have aregular shape (for example, but not limited to, defined by a length U1,width W, and height H).

When the first bed portion 1102-1 rotates relative to the second bedportion 1102-2, the position, shape, and/or size of the firstoverlapping working volume 1114-1 may change. For example, as shown inpart B of FIG. 11, the first overlapping working volume 1114-1 maytransform to overlapping working volume 1114-1′ having an irregularshape (for example, but not limited to, having a trapezoidal-likeprofile as viewed from a side of the overlapping working volume1114-1′). The origin of the global coordinates system 1120 remainsunchanged by the relative rotation of the bed portions. Unlike part A ofFIG. 11, the center (or centroid) of the overlapping working volume1114-1′ is not located at the origin of the global coordinates system1120 after the rotation. Instead, the center (or centroid) of theoverlapping working volume 1114-1′ may be offset from the origin of theglobal coordinates system 1120 by a vector T3 after the rotation.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” or “includes” and/or “including,” when used in thisspecification, specify the presence of stated features, regions,integers, steps, operations, elements and/or components, but do notpreclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components and/or groupsthereof

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top” may be used herein to describe one element's relationship to otherelements as illustrated in the figures. It will be understood thatrelative terms are intended to encompass different orientations of theelements in addition to the orientation depicted in the figures. Forexample, if the element in one of the figures is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on the “upper” side of the other elements. The exemplary term“lower” can, therefore, encompass both an orientation of “lower” and“upper,” depending upon the particular orientation of the figure.Similarly, if the element in one of the figures were turned over,elements described as “below” or “beneath” other elements would then beoriented “above” the other elements. The exemplary terms “below” or“beneath” can, therefore, encompass both an orientation of above andbelow.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. Numerous differentcombinations of embodiments described herein are possible, and suchcombinations are considered part of the present disclosure. In addition,all features discussed in connection with any one embodiment herein canbe readily adapted for use in other embodiments herein. It is intendedthat the following claims define the scope of the invention and thatmethods and structures within the scope of these claims and theirequivalents be covered thereby.

What is claimed is:
 1. A surgical tool having an electromagnetic (EM)sensor component, the surgical tool comprising: a flexible shaftportion; and a rigid portion attached to the flexible shaft portion,wherein the rigid portion comprises at least one EM sensor within therigid portion, wherein the at least one EM sensor comprises an extendedcore portion surrounded by a coil, wherein the at least one EM sensorextends along a majority of a length of the rigid portion, wherein thecoil extends along only a portion of a length of the extended coreportion, and wherein the at least one EM sensor generates a change involtage when exposed to an electromagnetic field.
 2. The surgical toolof claim 1, wherein the surgical tool is an endoscope.
 3. The surgicaltool of claim 1, wherein the rigid portion is a tip of the surgicaltool.
 4. The surgical tool of claim 1, wherein the at least one EMsensor has an internally extending core.
 5. The surgical tool of claim4, wherein the surgical tool is an endoscope.
 6. The surgical tool ofclaim 1, wherein the at least one EM sensor has an externally extendingcore.
 7. The surgical tool of claim 6, wherein the externally extendingcore comprises a force sensing component.
 8. The surgical tool of claim7, wherein the force sensing component has a spherical shape.
 9. Thesurgical tool of claim 1, wherein the at least one EM sensor has adiameter of approximately 300 μm.
 10. The surgical tool of claim 1,wherein the at least one EM sensor has ferrous core.
 11. A surgical toolhaving an electromagnetic (EM) sensor component, the surgical toolcomprising: a flexible shaft portion; and a rigid portion attached tothe flexible shaft portion, wherein the rigid portion comprises two EMsensors within the rigid portion, wherein at least one EM sensor of thetwo EM sensors comprises an extended core portion surrounded by a coil,wherein the coil of the at least one EM sensor extends along less than afull length of the extended core portion, and wherein the at least oneEM sensor extends along a majority of a length of the rigid portion. 12.The surgical tool of claim 11, wherein the two EM sensors are positionedobliquely with respect to each other.
 13. The surgical tool of claim 11,wherein the two EM sensors are positioned parallel with respect to eachother.
 14. The surgical tool of claim 11, wherein a first EM sensor oftwo EM sensors comprises an externally extended core portion and whereina second EM sensor of the two EM sensors does not have an extended coreportion.
 15. The surgical tool of claim 11, wherein a first EM sensor oftwo EM sensors comprises an internally extended core portion and whereina second EM sensor of the two EM sensors does not have an extended coreportion.
 16. The surgical tool of claim 11, wherein a first EM sensor oftwo EM sensors comprises an externally extended core portion and whereina second EM sensor of the two EM sensors comprises an internallyextended core portion.
 17. The surgical tool of claim 11, wherein atleast one EM sensor of the two EM sensors generates a change in voltagewhen exposed to an electromagnetic field.
 18. A surgical tool,comprising: a flexible portion forming a part of a shaft of anendoscope, wherein the flexible portion is configured to operablyconnect to a robotic arm; a rigid portion attached to the flexible shaftportion, wherein the rigid portion forms a tip of the endoscope; acamera in the tip of the endoscope; at least one illumination componentin the tip of the endoscope; a working channel in the tip of theendoscope; and at least one electromagnetic (EM) sensor in the tip ofthe endoscope, wherein the at least one EM sensor is configured to beused to spatially track the tip of the endoscope, wherein the at leastone EM sensor extends along a majority of a length of the tip, whereinthe at least one EM sensor is configured to generate a change in voltagewhen exposed to an electromagnetic field, wherein the at least one EMsensor comprises a core surrounded by a coil, and wherein the core butnot the coil of the at least one EM sensor extends from the rigidportion into the flexible portion.
 19. The surgical tool of claim 18,wherein the at least one illumination component comprises twoillumination components on opposite sides of the camera.
 20. Thesurgical tool of claim 18, wherein the at least one EM sensor comprisestwo EM sensors on opposite sides of the camera.
 21. The surgical tool ofclaim 18, wherein the at least one EM sensor comprises two EM sensorspositioned at non-parallel angles with respect to each other. 22.(Previously Pending) The surgical tool of claim 18, wherein the at leastone EM sensor comprises a single EM sensor that partially overlaps acentral axis of the tip.
 23. A surgical tool, comprising: a shaft; a tipattached to the shaft; at least one illumination component in the tip; aworking channel in the tip; a first electromagnetic (EM) sensorcomprising a first core and a first coil at least partially surroundingthe first core, wherein the first core is partially within the tip andpartially within the shaft, and wherein the first EM sensor extendsalong a majority of a length of the tip; and a second EM sensorcomprising a second core and a second coil at least partiallysurrounding the second core, wherein the second core is partially withinthe tip and partially within the shaft, wherein the second EM sensor ispositioned obliquely with respect to the first EM sensor, and whereinthe second EM sensor extends along a majority of the length of the tip.24. The surgical tool of claim 23, wherein the shaft is flexible and thetip is rigid.
 25. The surgical tool of claim 23, further comprising acamera in the tip, wherein the at least one illumination componentcomprises a pair of fiber optics illumination sources on opposing sidesof the camera.
 26. The surgical tool of claim 23, wherein the surgicaltool is an endoscope configured to be used in conjunction with a roboticarm to assist in surgery of a patient.
 27. The surgical tool of claim23, wherein each of the first and second coils is configured to induce avoltage when placed in an EM field, wherein each of the first and secondEM sensors is configured to output voltage information related to achange in the electromagnetic field as the position and orientation ofeach of the first and second EM sensors changes.